dobelmann



(No Mod el-j J. B. DOBELMANN. LAMP OHIMNEY.

No. 256,796. Patented Apr. 18,1882.

J y.- z

INVENTOR:

WITNESSES ATTORNEY.

N. PETERS, Phoio-Llthognpher. WalhingQUn. D c.

UNITED STATES JOHN B. DOBELMANN, OF BROOKLYN, YORK, ASSIGNOR TO ADELE j PATENT OFFICE. j

LOUISE DOBELMANN, OF SAME PLACE.

LAMP-CHIMNEY.

SPECIFICATION forming part of Letters Patent N0. 256,796, dated April 18, 1882.

Application filed January 2], 1862.

To all whom it may concern:

Be it known that I, JOHN B. DOBELMANN, of Brooklyn, in the county of Kings and State of New York, have invented a new and useful Improvement in Lamp-Chimneys; and I do hereby declare that thefollowing is a full,clear, and exact description thereof.

My invention relates more particularly to chimneys for lamps such as are used in lighthouses. Such chimneys have heretofore been made by blowing them into shape and afterward finishing them by hand with suitable tools. By this process it has been found impossible to make them perfectly true and of uniform shape and size, in consequence of which considerable loss has been incurred through breakage of the chimneys.

To obviate the disadvantages heretofore experienced is the object of my invention; and to this end my invention consists in a novel construction and an improved form of the chimney, whereby provision is made for strengthening the chimney and for securing uniformity of shape and size in any number of chimneys which may be made; and in the employment, in connection with the chimney, of a jacket at the bottom, whereby the bottom of the chimney is protected, as hereinafter more particularly described.

In carrying out my invention the chimney is made in a mold while the glass is in a pliable state. The top and bottom of the chimney are cut oil exactly at a right angle with the major axis of the chimney, which is then allowed to cool, so as to insure to the top and bottom ends a perfectly circular form. These ends are afterward ground perfectly true, and ajacket is applied to the lower end, as hereinafter more particularly described. Near the lower end of the chimney a bead or corrugation is formed for the purpose of giving additional strength to the chimney.

The accompanying drawings illustrate a mode of carrying out my invention.

Figure 1 is a side elevation, and Fig. 2 a central vertical longitudinal sectional view of a chimney embodying my improvements.

The chimney A is made with the usual swell at the lower portion, terminating in a (N0 model.)

cylindrical form in the upper portion. Near the baseor lower end of the chimney is a bead or corrugation, B, extending entirely around the chimney. This chimney is made in a metallic mold, and thus a perfectly true shape and uniformity of size of all the chimneys made in said mold are insured. The waste at the upper and lower ends of the chimney is cut ofi' at a right angle with the length, and the edges of these ends are then ground perfectly true.

In order to provide against any disadvantage which might result from thegrinding of the edge of the glass, and thus exposing its porosity, the head or corrugation B is formed, so that in the event of the heat at the base of the chimney being sufficiently great to start a break or crack in the glass such break or crack is arrested by the bead B and prevented from ascending any higher.

In order to still further protect the ground edge of the end of the chimney, I employ a jacket at the bottom, made of sheet metal, stamped or formed in any suitable manner.

The jacket (l consists of avertical band having a horizontal rim or flange turned inward from its lower edge. The jacket fits on the base or lower end of the chimney, which lower end has its edge resting on the inwardlyturned rim or flange. This rim or flange serves as a protection to the porous ground edge of the glass, while the vertical band portion prevents the separation or flying apart of portions of glass in the'event of breakage.

If fdesircd, there may be a cement, rubber, or other suitable packing between the rim or flange and the edge of the glass.

What Iclaim as new, and desire to secure by Letters Patent, is-- 1. The combination of a molded glass chimney having its lower edge ground true, as described, and provided with a corrugation, B, and a smooth metallic jacket or band, 0, applied to the lower end of the chimney, but unattached thereto, so as to be readily removed and replaced without detaching and attaching fastening devices, the lower end of said jacket or band being bent inward at right angles to the axis of the chimney, and terminating at the inner surface of the vertical wall of the inward at rightangles, and terminating at the 10 chimney, substantially as and for the purpose inner surface of the vertical wall of the chimset forth. I ney, substantially as and for the purpose de- 2. The combination of a molded glass chiinscribed.

5 ney having its lower edgeground true as de- T scribed, and provided with a corrugation, B, DQBELMANI" and. a smooth metallic jacket or band, 0, ar- Witnesses: ranged loosely on the lower end of the said E. R. BROWN, jacket or band, and having its lower cdgebent O. SEDGWICK. 

